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zepelin [54]
3 years ago
7

Please help me with this question.

Mathematics
1 answer:
CaHeK987 [17]3 years ago
4 0

Answer:

24

Step-by-step explanation:

Let's say that R, N, and M are the ages of Ric, Nancy, and Michael in 1980.

We can write three equations:

R = 2N

N = 2M

(R + 12) + (N + 12) + (M + 12) = 78

Simplify the third equation:

R + N + M + 36 = 78

R + N + M = 42

Substitute the first equation:

2N + N + M = 42

3N + M = 42

Substitute the second equation:

3(2M) + M = 42

6M + M = 42

7M = 42

M = 6

Therefore:

N = 12

R = 24

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garri49 [273]

Answer:

I believe the second is wrong

4 0
3 years ago
The vendor of a coffee cart mixes coffee beans that cost $9 per pound with coffee beans that cost $5 per pound. How many pounds
lidiya [134]

Answer:

56.25 pound of the coffee that costs $5 per pound is needed

18.75 pound of the coffee that costs $9 per pound is needed

Step-by-step explanation:

Let the number of pounds be x and y respectively

The total pounds is 75;

So;

x + y. = 75 •••••••(i)

Total cost of first type

9 * x = $9x

Total cost of second type;

5 * y= $5y

75 pound at $6 per pound; total cost of this is;

6 * 75 = $450

Thus;

9x + 5y = 450 ••••••••(ii)

From i, x = 75-y

Put this into ii

9(75-y) + 5y = 450

675 -9y + 5y = 450

4y = 675-450

4y = 225

y = 225/4

y = 56.25

x = 75 - y from i

x = 75-56.25

x = $18.75

8 0
3 years ago
Please help me answer this
Eduardwww [97]

Answer:

The 2nd y is 12, the 3rd y is 24 and the last x is 3

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
NEED HELP ASAP!!!!!!
Montano1993 [528]

Answer:

I'm pretty sure its 2.9 hours

Step-by-step explanation:

hope this helps

3 0
2 years ago
Please help giving brainless to the first person to help me. Thank you
kotykmax [81]

Answer:

Step-by-step explanation:

To find the population density of any state:

We must divide the population number by the area

Thus Washington state's population density equals 7,705,281 / 71297.95

Which equals 108.1

Hope that helps!

4 0
2 years ago
Read 2 more answers
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